Vending machines designed to vend a single type of merchandise have long been popular, particularly where the article vended has achieved a high volume of sales. In such situations, there is a need to provide sizeable storage capacity in the vending machine to minimize the intervals between visits to the machine by a service person, and thus reduce operating costs. Commonly, articles vended from a machine are dispensed by gravity, favoring their disposition in vertical stacks, one on top of another. The storage capacity limitation imposed by height constraints has led the vending machine industry to resort to "double-acting" vending mechanisms in which identical articles are stored in vertical stacks in adjacent compartments, the articles alternately being dispensed from each.
Such a device is shown in U.S. Pat. No. 3,970,181, in which a dispensing foot is moved back and forth in a pendular arc between adjacent compartments, ejecting merchandise in turn from each in the vending process. In the machine, the foot moves through a relatively wide gap provided in the support members forming the shelf on which the articles to be vended rest, enabling the foot to contact the edge of the articles and push them from the device. Unfortunately, the sizeable gap between the support members required to accomodate access by the foot makes it difficult, or in some cases impossible, to vend products narrower than the gap. This seriously limits the versatility, and therefore, the usefulness of the machine.
Furthermore, when a pendulum structure is directly used as a means by which articles are dispensed from adjacent compartments in a double-acting vending machine, dispensing of the merchandise must necessarily occur in two, opposite directions. This necessitates provision for ejection space at each side of the machine, requiring relatively wide machines, which in some cases are undesirable.
In addition, the machine taught in the patent referred to requires a direct connection between the cam which actuates the pendulum structure, and the operating handle of the machine. Such a connection undesirably limits the ease with which the mechanism can be operated.